Eeschema, Libedit: Fix bug that can crashes Eeschema: In libedit 2 mandatory fields could be deleted. Fixed now.
Very minor other fixes.

 fix a compil warning.
CvPcb: fix regressions :
 Shows now a void field instead of the dummy footprint name $nonane (whenthere is  no footprint selected in netlist).
 The active footprint selection changes only if a new component is selected from the component file,
 and does not change just when the next component is automatically selected, after a footprint selection.
 Speed up delete association and auto associe.

Add patch from Lorenzo Marcantonio. Fix some warning issues, and zlib issue under Windows (zlib sources added)

All: change MILS_TO_IU_SCALING_FACTOR constant to IU_PER_MILS ( and MM_TO_IU_SCALING_FACTOR to IU_PER_MM)
Also fix bug 985654.

All: change MILS_TO_IU_SCALING_FACTOR constant to MILS_PER_IU  ( and  MM_TO_IU_SCALING_FACTOR to MM_PER_IU)
Also fix bug 985654.

Other scaling factors (MILS_TO_IU_SCALING_FACTOR and DECIMILS_TO_IU_SCALING_FACTOR)
also defined only in convert_to_biu.h.
Allows different scaling value for Gerbview.
Needs more tests.

* Remove internal units from BASE_SCREEN and it's derivatives.
* Remove internal units from EDA_DRAW_FRAME and it's derivatives.
* Use build time code to replace internal units conversions.
* Fix scaling bug in page layout sample window that I created in my
  last commit.

* Move all convert from user to internal units into base_units.cpp.
* Remove internal units parameters from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Remove internal units from all dialog text control helper classes.

* Scale page reference border and title block, grid sizes, and zoom factors
  correctly for nanometers.

Other minor fixes.

* Move all convert from internal to user units functions into separate file.
* Remove internal units parameter from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Compile these conversion routines separately for the appropriate pcb or
  schematic internal units.
* Move internal units specific status bar update code into the appropriate
  application for updating the status bar.
* Move millimeter user units rounding function to common.cpp.

drawframe.cpp: commit a fix about scrollbars  from lajos kamocsay

If enable in preference menu, allow the pan with drag mouse with middle button down.
both unlimited and limited pan is allowed.

Eeschema: one string with a bad char (\a, not useable in internationalized strings).
Dialog_page_settings: use not translated strings in code, so strings can be freely translated for the UI.
(Initial code was not working with existing translations)
Update 2 icons.

* BLOCK_SELECTOR class is not longer derived from EDA_ITEM.
* Encapsulate BLOCK_SELECTOR class member variables and add access methods.
* Move HandleBlockBegin() function from block_commande.cpp to drawframe.cpp.
* Remove virtual methods from top level derived objects per future
  coding policy change.
* Remove Doxygen copydoc statement from objects derived from EDA_ITEM
  since the comments are automatically copied to the derived object.
* Removed copy and pasted Doxygen comments from objects derived from
  EDA_ITEM.

subclass DIALOG_SHIM support.
Tried dialog_drc but it has nesting problems due to use of DRCLISTBOX, which
needs to be put into its own header file to untangle.

Add include/dialog_shim.h and common/dialog_shim.cpp for use by wxformbuilder's "subclass a wxDialog" support.
This works, but in my version of wxformbuilder there is a bug which does not properly show the 
subclass property, even though it is still in play.  This happens after saving then loading the *.fbp file.
So it is a nuisance bug, but does not affect functionality.

Remove 2 duplicate icons.
Minor cosmetic enhancements and fixes in popup menus.

All: added a standard exit dialog called by int DisplayExitDialog( wxWindow* aParent, const wxString& aMessage )
Called when closing pcbnew, cvpcb and eeschema.
Minor code cleaning: remove duplicate or not used strings (mainly file extensions and wildcards)

wxWidgets 2.9 knows wxSVGFILEDC device context.
Unfortunately, arcs are drawn as pies (this is a feature, not a bug).
This is not correct for Kicad.
So Kicad has its own wxSVGFILEDC (named KicadSVGFileDC) that is basically the same as wxSVGFILEDC,
but with arcs drawn as arcs, not pies.
Note also under wxWidgets 2.8 does not know wxSVGFILEDC , so kicad had already its own SVG device context.

other minor fixes.

* Pcbnew: in hight contrast mode the 'V' hotkey did not always refresh the screen.
* Eeschema: incorrect print scale when the option 'Show page limits' is disable.

Eeschema: Viewlib is now accessible from Libedit (to browse libs or load a component to edit)
Libedit: uses now the same dialog as the schematic editor to load a component
Some code cleaning.